Heavy duty stapler



FIG. 1 is a right side elevational view of a heavy duty stapleraccording to the present invention;

FIG. 2 is a front and right side perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is a rear elevational view thereof.

The ornamental design for a heavy duty stapler, as shown and described.